1. Field of the Invention
This invention relates to a metering device of a single lens reflex camera.
2. Description of the Prior Art
There have recently been proposed various metering systems in which a phototaking picture is divided into a plurality of metering areas and the exposure of the entire phototaking picture is determined on the basis of the metering output regarding each of the metering areas.
For example, Japanese Laid-Open Patent Application No. 17725/1978 discloses a technique whereby the light-receiving surface of a photoelectric device is divided into a number of light-receiving portions and an object image formed on a focusing plate by a phototaking lens is reduced and projected upon said light-receiving surface by a relay lens so that exposure is determined by the metering output from each of the light-receiving portions of the light-receiving surface.
However, this technique has the following disadvantages. Since said reduced projected image must properly correspond to the object image formed by the phototaking lens, the relay lens must cover the entire object image formed by said phototaking lens and accordingly, must be a relay lens having a wide angle of view and a high performance which means a high cost. This prevents the metering device from being made compact and also requires the photoelectric device to have a large light-receiving surface. Further, since the light-receiving surface corresponds to the phototaking picture, any positional error of the relay lens or the light-receiving surface of the photoelectric device may result in an error of metering. Accordingly, the relay lens and the photoelectric device must be arranged with high accuracy.